Andy, send detailed pictures if you can of all the connections.? Firm doesn't mean it's plugged in correctly per Raj's advice.
The Nano is not only built upside down for historical reasons, but could be clocked 180 degrees out when you inserted it.
the snap-able headers used can also easily throw off your alignment.
Some folks here have also mistakenly connected the encoder to the main board audio connection as the connector 'fits'
Check that the solder bridge is placed for jumper J1 on the display.
If that is open, you will get a white screen.? (although won't affect the audio)
"No" audio is also a little strange.? You should get some indication out of the speaker even without the raduino plugged in.
with no input to the LM386, you should have some level of detectable noise.?
Stick with it as all issues can be corrected.
Rgds,
Gary
